In order to study the volatilization characteristics of biomass particles at flash heating rates, a plasma heated laminar entrained flow reactor (PHLEFR) was designed and built in our lab. Two agricultural residues, wheat straw and corn stalk, were chosen as feedstock for pyrolysis which were conducted on the PHLEFR with the aim of determining the extent of thermal decomposition at high heating rate (more than 10(4) degrees C s(-1)). Based on the experimental data, a first order kinetic model was introduced and the relevant kinetic parameters (apparent active energy and apparent frequency factor) were determined for the two straws: E = 31.51 kJ mol(-1), A = 1028 s(-1) (wheat straw) and E = 33.74 kJ mol(-1), A = 1013 s(-1) (corn stalk). The predicted conversion of the fitted model to the experimental data provided general agreements when one considered the experimental errors. (c) 2005 Elsevier Ltd. All rights reserved.